1. Field of the Invention
This invention relates to a connecting mechanism for connecting two member together, and more particularly to a connecting mechanism for detachably connecting together the respective ends of two rod members of a space craft structure, a space station structure, and the structures of any other mechanisms, apparatuses, tools or the like.
2Description of the Related Art
There have been developed various kinds of foldable and extendible truss structures of space crafts, space stations and the like. They have hinge mechanisms connecting together the respective ends of a plurality of rod members of the truss structure which is folded or extended at the hinge mechanisms so as to take their predetermined folded or extended shapes.
Such a truss structure occupies a small volume when it is folded. It is launched by a rocket or the like into the space in a folded state and is extended into a required developed shape in the space.
Although the truss structure has a complicated structure in an extended state in general, it is designed so as to occupy a minimum volume in a folded state. In this regard, rod members around the hinge mechanisms draw complicated loci when the truss structure is folded and extended. Since five or six rod members are connected to a hinge mechanism in general, the hinge mechanism has a very complicated structure. This results in a heavy weight, a poor reliability and a high manufacturing cost of the hinge mechanism. Many kinds of truss structures must be manufactured in order to obtain many different extended states. Thus, many different kinds of complicated hinge mechanisms must be made according to the different truss structures, leading to a high manufacturing cost.
An attempt has been made to develop an extending type truss structure which uses, instead of hinge mechanisms, detachable connecting mechanisms for connecting the respective ends of rod members together. The detachable connecting mechanism comprises a main body to which the respective ends of rod members are removably connected, flexible wires extending through the main body and the rode members, and springs housed in the rod members for giving a tension to the wires.
When the rod members are pulled out from the main body, they have come to be connected to the main body only by the wires so as to be rotated to be directed in any directions, whereby the truss structure can be folded or extended. In the extended state, on the other hand, the respective ends of the rod members are fixedly fitted to the main bodies, whereby the required truss structure is formed.
It is preferred that each connecting mechanism used in such an extendible truss structure is constructed such that the respective ends of the rods are securely and fixedly fitted to the main body only by the tension of the wires when the ends of the rod members are pulled toward the main body only by the tension of the wires.